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THE COOLING ENGINE
The really interesting part of the e-Otonashi is the bottom, however. It is what it looks like: The entire bottom of the case is a massive black-anodized aluminum heatsink. Two of the fins, one at the front and one at the back, have a hard rubber sleeve over the entire length: These act as the feet, and elevate the rest of the fins up a few millimeters, presumably to aid in air circulation and avoid possible heat damage to the desk surface.
Three thumbscrews on the back hold the cover in place. The cover is fairly thin. Here's what the interior looks like.
The top piece with the circular cutouts is the mounting bracket for both the hard drive and the optical drive. It comes off with the removal of 4 screws on the side frames.
With the mounting bracket removed, the core CPU cooling engine is revealed. It is this silver colored J-shaped aluminum bar, clamped with brackets on the ends to the flat surface of the case bottom, the big heatsink. It is an aluminum heatpipe with a flat profile.
Here's a closer look at the heatpipe.
And the mating surface of the aluminum heatsink below it.
Only the heatsink surface beneath the heatpipe is exposed. The bottom sheet metal of the case has a cutout just big enough to fit the the heatpipe.
QUESTIONS ABOUT HEATPIPES
Just how this heatpipe is affixed to the CPU on a Mini-ITX board will be shown in the following photos. In the meanwhile, consider the flat heatpipe itself.
TS Heatronics, who manufactures this heatpipe, says their technology is a significant improvement over conventional heatpipes. A conventional heat pipe transfers heat through a cycle of vaporization, transportation, and then condensation of a working fluid with a low boiling temperature. It depends on gravity to allow the condensed water to flow back down to the heat source, and thus must work with the evaporator (and heat source) at a lower point and the condenser (radiator or heatsink) at a higher point. According to TS Heatronics, their...
Heatlane technology is called meandering capillary tube heat pipe, or self-excited oscillation (pulsation) heat pipe or Akachi pipe named after Hisateru Akachi, the inventor who is former vice president (now consultant) of our company. The technology is, with its epoch-making features, attracting deep concern of companies, universities and research institutes all over the world, resulting in the award of the technology prize of the Japan Association for Heat Pipe for the year 2002... The technology realizes effective heat transfer conducted not only horizontally but also from top to bottom (top heat) as well as better heat transfer capability than the conventional heat pipe.
Before assembling a system in this case, I thought about how I could witness the heat transfer property of this heatpipe first hand. The answer came to me when I was boiling some water for a cup of tea.
I found a piece of light architectural aluminum channel in my workshop and cut it to the same length as the flat heatpipe from the e-Otonashi. I poured piping hot, just boiled water into a large coffee mug. I placed the aluminum channel piece in the cup of hot water and held the end with my thumb and index finger. In about 10 seconds, it became too hot to hold. The aluminum channel was removed, and the TS Heatronics heatpipe was put in its place. It took only 2~3 seconds before the end became too hot for me to hold! This was a dramatic and simple illustration of the thermal transfer power of the heatpipe.
The same thing was also tried with a glass of ice cold water. Again, the speed with which the heatpipe became freezing cold was astonishing. My only regret is that I do not have any conventional heatpipes to compare against the Heatlane version.